From Protons to Picasso: Recreating Famous Paintings Using Proton Beams as a “Paintbrush”

Abstract

To many, medicine is just as much an artform as it is a science. From the colorful stains used in diagnostic pathology, to the tactile sculpting of surgery, to the dose painting in radiation oncology, there is beauty and art to be found across all disciplines. In pencil-beam-scanning proton therapy, the dose is painted layer-by-layer, spot-by-spot, allowing for significantly more control compared to conventional radiation. This work intends to showcase the immense capability of intensity-modulated proton therapy (IMPT) through the recreation of some of the most renowned artworks throughout history, and has potential applications in patient education, medical/physics education, and quality assurance. Five (5) well-recognized paintings spanning from the Golden Age to the modern era were recreated as treatment plans in the Eclipse (version 16.1) External Beam Planning environment. For each "painting" (treatment plan), clinical protons within the range of 70-250 MeV were used to deposit "paint" (radiation dose) onto a "canvas" (water phantom) to a prescription of 100 Gy. The individual elements of each artwork were first delineated as separate structures. Colors were then assigned to appropriate isodose lines to mimic the corresponding palettes found in the original artworks. For each treatment plan, a single field was used along with inverse optimization to deposit the different doses at a depth of 10 centimeters. The resulting dose distribution was calculated with the proton convolution-superposition algorithm used in clinical practice. The dose distributions of the "paintings" demonstrated a marked semblance to the original artworks with sufficient resolution to elucidate fine details. The "paintings" varied in dimension from 20-30 cm at isocenter and on average took between 5-6 hours to complete. The number of structures used for planning ranged from 6-65 depending on the style and complexity of the original artwork. For a fractional dose of 200 cGy, the number of monitor units ranged from 73,145-269,970. With the advent of IMPT and modern planning techniques, we can now realize increasingly complex treatment plans, allowing for the creation of dose distributions that are highly targeted and specific. This is demonstrated by the capability to create recognizable works of art using proton beams as a "paintbrush".